We should be able to set the environment variable PATH in an Azure Pipelines job with echo '##vso[task.prependpath]$HOME/miniconda3/bin'. See https://github.com/pandas-dev/pandas/blob/master/azure-pipelines.yml#L27

But that didn't work when we implemented it, so we ended up setting the path manually in every step (e.g. https://github.com/pandas-dev/pandas/blob/master/azure-pipelines.yml#L48).

This is adding noise to our CI configuration, making it harder to see what every step is doing. We should try to understand what's the problem with setting the PATH, and fix it.

This also applies to ci/azure/posix.yml (besides azure-pipelines.yml in the root).